<div class="offcanvas offcanvas-top" tabindex="-1" id="offcanvasTop" aria-labelledby="offcanvasTopLabel"
     style="height: 50%">
    <div class="offcanvas-header">
        <h5 class="offcanvas-title" id="offcanvasTopLabel">购物车</h5>
        <button type="button" class="btn-close" data-bs-dismiss="offcanvas" aria-label="Close"></button>
    </div>
    <div class="offcanvas-body">
        ...
    </div>
</div>